To provide a double spindle headstock capable of increasing a turn speed and shortening cycle time by reducing a weight of a turning head body and inertia.
This double spindle headstock is constituted such that a first spindle device 27 and a second spindle device 28 which hold a workpiece are arranged at a predetermined interval, the turning head body 26 attached turnably to a headstock body 21 is turned and indexed by a turn and drive device 45 so that the first and second spindle devices are alternately indexed to a machining position A and a loading position B, and rotation is given to the first spindle device 27 or the second spindle device 28 indexed to the machining position through a clutch mechanism from a rotation and drive device 43 arranged in a headstock fixing part to hold a turn and indexing position of the turning head body 26 by a movable knock pin device 50. Since it is unnecessary to provide a spindle driving motor in the turning head body and the weight of the turning head body and inertia can be reduced, the turning speed can be increased and cycle time can be shortened.
OTSU YUKIO
MARUYAMA TOSHIO
MIYATA SEIJI
